The Mellotron Group

I have been amusing myself trying to play Dance of the Fire Witch from "In the court of..", can anybody play trills on a mellotron? Mine isn't in the greatest of shape and the keyboard  is a bit of a compromise between touch and reliabilty of getting the note to play, so the action is a bit heavy. On a tron in good condition is it possible? I can't remember having heard one recorded.

Mark